Limited number of concurent threads C#

Question

I have a list of urls, and I want to download the source code using the WebClient class. Let's say that I have this urls:

private static string[] urls = 
{
   "google.com",
   "yahoo.com",
   "msn.com",
   "bing.com",
   "omarion.com",
   "bowwow.com"
};

It's a list of 6 urls. I want to use just 2 threads (at the same time) to download the source code.

I've seen that an option would be this:

private void RunAllActions(IEnumerable<Action> actions, int maxConcurrency)
{
    using(SemaphoreSlim concurrencySemaphore = new SemaphoreSlim(maxConcurrency))
    {
        foreach(Action action in actions)
        {
            Task.Factory.StartNew(() =>
            {
                concurrencySemaphore.Wait();
                try
                {
                    action();
                }
                finally
                {
                    concurrencySemaphore.Release();
                }
            });
        }
    }
}

but I don't know how to properly use it.

The idea is that I have an X number of links, but I want just Y threads working at the same time.

I've tried to do it with ThreadPool, but if I specify 5 threads, that number is not really taken into consideration. With this I mean, that even if I specify to run 5 threads at a time, 8 thread might start, or just 3 threads, depending on ... the situation I guess.

@L.B Your answer there talks abouts any action in general, this is mroe specific. You dont need to use threadpool threads at all to achieve what you want, and he doesn't need it. — Yuval Itzchakov, Aug 25 '14 at 14:31
@YuvalItzchakov just replace the comment in that answer with `action();` — L.B, Aug 25 '14 at 14:32
@L.B No, you dont need to use `Task.Factory.StartNew` at all, and he doesn't need a general `Action`. Also, your code there uses a block `Wait`, which isn't needed either. — Yuval Itzchakov, Aug 25 '14 at 14:33
Looks like I found my solution. The question was marked as duplicated (and thanks to L.B for doing so). Here is the answer: http://stackoverflow.com/questions/14075029/have-a-set-of-tasks-with-only-x-running-at-a-time — user1812076, Aug 25 '14 at 14:45

Limited number of concurent threads C#

0 Answers0